This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A239335 #7 Jun 02 2025 09:26:11 %S A239335 12,172,2187,27341,346028,4360887,54774178,688266175,8649330696, %T A239335 108663198449,1365050486095,17148274201252,215420739233431, %U A239335 2706135761424448,33994663679676011,427043158643798758 %N A239335 Number of nX3 0..3 arrays with no element equal to one plus the sum of elements to its left or three plus the sum of elements above it, modulo 4. %C A239335 Column 3 of A239340 %H A239335 R. H. Hardin, <a href="/A239335/b239335.txt">Table of n, a(n) for n = 1..210</a> %H A239335 R. H. Hardin, <a href="/A239335/a239335.txt">Empirical recurrence of order 64</a> %F A239335 Empirical recurrence of order 64 (see link above) %e A239335 Some solutions for n=4 %e A239335 ..0..0..0....2..0..0....0..0..2....2..0..0....0..2..2....0..0..2....0..0..2 %e A239335 ..0..2..0....0..2..0....2..2..0....0..0..0....0..0..3....2..2..2....2..2..0 %e A239335 ..0..2..2....2..2..0....0..0..0....0..0..2....0..0..3....0..3..1....3..2..3 %e A239335 ..2..2..3....2..0..0....2..0..2....0..0..3....0..2..0....0..2..2....3..1..2 %K A239335 nonn %O A239335 1,1 %A A239335 _R. H. Hardin_, Mar 16 2014